Calling All Athletes: Carbohydrate and Protein Intake


Carbohydrates are the primary source of muscle energy. Complex carbohydrates such as bread, whole grains and pasta get broken down into glucose, a pure form of nutritional energy, and then stored as glycogen in the liver and the muscles for use as fuel. Simple sugars such as fructose, dietary glucose and processed flours and cereals don’t need to be broken down so they are absorbed more rapidly. The problem with this  form of quick energy is that it tricks the body into thinking there is an ample supply of glucose steadily entering the bloodstream, when in fact it’s just a short burst. The sugar high is a result of the bloodstream gathering up all the glucose, but inevitably it’s followed by a sugar low, since the glucose is short-lived and easily depleted. It’s true, however, that a low-fat candy bar or sports drink containing simple sugars can provide quick, useful energy if taken immediately prior to exercise, but ingesting fat prior to exercise can cause stomach problems.

Complex carbohydrates provide a natural, more even distribution of energy. They make use of the body’s innate processing abilities so that glucose is released gradually into the bloodstream. Glycogen is replenished by the slow-burning complex carbohydrates on an ongoing basis.

Years ago, athletes consumed high volumes of meat protein like with steaks as protein was king. The reasoning behind this is that muscle tissue is made up of protein strands, so the thinking was that eating more protein would build more muscle. However, in the 1960‘s, researchers established that protein doesn’t fuel muscle, carbohydrates do. In fact, as a pre-event food, protein can diminish performance because it’s difficult to digest and when in the stomach, draws blood away from the working muscles. Meats offer the most complete proteins, they have a full compliment of amino acids needed to create enzymes and hormones, fight off infection, help in the elimination of wastes and build cell membranes. However, because most meats are high in saturated fats, and implicated in heart disease, meat intake should be moderate at best. Other good sources of amino acids are fish and chicken, which also provide amino acid balance similar to human tissue proteins. While plant sources contain amino acids as well, they tend to be deficient in tryptophan and lysine. Soybeans, beans and other legumes are next in line; at the bottom of this pyramid are grains and cereals.

The U.S. government’s recommendation for protein intake, which does not take into account level of activity, is .8 grams of protein per kilogram of body weight per day, or about 12% of total calorie consumption. Each gram of protein has four calories, so that comes out to about 250 calories per day, which can obtained by consuming about 8 ounces of meat, chicken or fish.

To ensure that the body maximizes the use of available protein, make sure to consume enough carbohydrates. When carbohydrate intake is insufficient, the body will convert higher amounts of protein into glucose for use as energy, which means less available for repairing muscle tissue. By sticking to a diet that favors carbohydrates over proteins, the body will use the protein for the purpose it was designed.

Because of its association with cardiovascular disease, fat intake should comprise no more than 30% of one’s diet, and preferably closer to 10%. However, percentage isn’t the only factor to consider; the type of fat consumed is also important. In France and Greece, where many rural-living people subsist on traditional diets that are as high as 45% in fat calories, studies have shown an extremely low incidence of heart disease. This is because the fats consumed by are derived mostly from olive oil; which are monounsaturated, high in the antioxidant vitamin E, and apparently increases levels of HDL, or good cholesterol. By contrast, the American diet is high in saturated fats, which are saturated with hydrogen atoms, and derived from meats most likely to lead to atherosclerosis, or clogged arteries. 

The Mediterranean diet is also distinguished by other protective factors not common to the typical American diet; high consumption of fresh fruits and vegetables, low consumption of meats, moderately low consumption of dairy products, and moderate consumption of alcohol, which also seems to increase HDL. A study of post heart attack patients placed on the Mediterranean diet found that they were 75% less likely to suffer from follow-up illness or death than patients who were placed on a highly fat-restricted diet.

Americans spend about 6 billion annually on nutritional supplements in the form of packaged vitamins, minerals, protein powders and amino acids. Supplement use is highest among athletes who are considered the most well-informed about health research. In the past 10 years a plethora of products have been touted as muscle building aids, fat loosing and energy boosting, but with few exceptions, there’s no evidence that these expensive products work. Studies have shown that athletes who take mineral, vitamin and protein supplements for long periods of time fare no better than those who don’t when both groups are eating an otherwise balanced, healthy diet.